A semiconductor device comprising stacked complimentary transistors are described. In some embodiments, the semiconductor device comprises a first device comprising an enhancement mode III-N heterostructure field effect transistor (HFET), and a second device over the first device. In an example, the second device comprises a depletion mode thin film transistor. In an example, a connector is to couple a first terminal of the first device to a first terminal of the second device.

An electronic circuit having a semiconductor device is provided that includes a heterostructure, the heterostructure including a first layer of a compound semiconductor to which a second layer of a compound semiconductor adjoins in order to form a channel for a 2-dimensional electron gas (2DEG), wherein the 2-dimensional electron gas is not present. In aspects, an electronic circuit having a semiconductor device is provided that includes a III-V heterostructure, the III-V heterostructure including a first layer including GaN to which a second layer adjoins in order to form a channel for a 2-dimensional electron gas (2DEG), and having a purity such that the 2-dimensional electron gas is not present. It is therefore advantageous for the present electronic circuit to be enclosed such that, in operation, no light of wavelengths of less than 400 nm may reach the III-V heterostructure and free charge carriers may be generated by these wavelengths.

Embodiments of this application relate to the field of semiconductor technologies, and provide a composite substrate and a preparation method thereof, a semiconductor device, and an electronic device. The composite substrate includes a bearer layer, a silicon carbide layer, and at least one epitaxial layer. The silicon carbide layer is disposed on the bearer layer and bonded to the bearer layer, and a material of the silicon carbide layer includes monocrystal silicon carbide. The at least one epitaxial layer is disposed on a side that is of the silicon carbide layer and that is away from the bearer layer.

A high electron mobility transistor includes a stack of layers including a passivation layer and a heterojunction including a first semiconductor layer, a second semiconductor layer and a two-dimensional electron gas at the interface thereof, one surface of the passivation layer being in contact with the first semiconductor layer; a source metal contact and/or a drain metal contact and a gate electrode; an n+ doped zone situated inside the heterojunction; the source metal contact and/or the drain metal contact being positioned at the level of a recess formed in the stack of layers, the source metal contact and/or said drain metal contact having a thickness defined by an upper face and a lower face substantially parallel to the plane of the layers, the upper face being planar, the lower face being in contact with the n+ doped zone and below the interface between the first and second semiconductor layers.

According to one embodiment, a semiconductor device includes a first crystal region, a second crystal region, a third crystal region, and a fourth crystal region. The first crystal region includes magnesium and Al.sub.x1Ga.sub.1-x1N (0≤x1<1). The second crystal region includes Al.sub.x2Ga.sub.1-x2N (0<x2≤1). The third crystal region is provided between the first crystal region and the second crystal region. The third crystal region includes oxygen and Al.sub.x3Ga.sub.1-x3N (0≤x3≤1 and x3<x2). The fourth crystal region is provided between the third crystal region and the second crystal region. The fourth crystal region includes Al.sub.x4Ga.sub.1-x4N (0≤x4<1 and x4<x2).

A semiconductor device includes; a semiconductor substrate; an emitter electrode provided on the semiconductor substrate; a gate electrode provided on the semiconductor substrate; a drift layer of a first conduction type provided in the semiconductor substrate; a source layer of the first conduction type provided on an upper surface side of the semiconductor substrate; a base layer of a second conduction type provided on the upper surface side of the semiconductor substrate; a collector electrode provided below the semiconductor substrate; and a two-part dummy active trench including, at an upper part, an upper dummy part not connected with the gate electrode and including, at a lower part, a lower active part connected with the gate electrode and covered by an insulating film, in a trench of the semiconductor substrate, wherein a longitudinal length of the lower active part is larger than a width of the lower active part.

An N-polar III-N high-electron mobility transistor device can include a III-N channel layer over an N-face of a III-N backbarrier, wherein a compositional difference between the channel layer and the backbarrier causes a 2DEG channel to be induced in the III-N channel layer adjacent to the interface between the III-N channel layer and the backbarrier. The device can further include a p-type III-N layer over the III-N channel layer and a thick III-N cap layer over the p-type III-N layer. The III-N cap layer can cause an increase in the charge density of the 2DEG channel directly below the cap layer, and the p-type III-N layer can serve to prevent a parasitic 2DEG from forming in the III-N cap layer.

A nitride semiconductor device includes a substrate, a drift layer and a block layer sequentially provided above the substrate, a gate opening penetrating through a block layer and reaching a drift layer, an electron transit layer and an electron supply layer sequentially provided above the block layer and along the inner surface of the gate opening, a gate electrode provided to cover the gate opening, a source opening penetrating through an electron supply layer and an electron transit layer and reaching the block layer, a source electrode provided in the source opening, and a drain electrode on the rear surface side of the substrate. Seen in a plan view, at least part of an outline of an end of the gate opening in the longitudinal direction follows an arc or an elliptical arc.

There is disclosed a structure in a wide band gap material such as silicon carbide wherein there is a buried grid and shields covering at least one middle point between two adjacent parts of the buried grid, when viewed from above. Advantages of the invention include easy manufacture without extra lithographic steps compared with standard manufacturing process, an improved trade-off between the current conduction and voltage blocking characteristics of a JBSD comprising the structure.

A heterostructure, includes: a substrate; and a buffer layer that includes a plurality of layers having a composition Al.sub.xIn.sub.yGa.sub.1-x-yN, where x≤1 and y≥0; wherein the buffer layer has a first region that includes at least two layers, a second region that includes at least two layers, and a third region that includes at least two layers.